This is the application by the Division of Maternal Fetal Medicine at the Ohio State University for continued participation in the NICHD Maternal Fetal Medicine Units Network. The Network's purpose is to improve health outcomes for pregnant women and infants by conducting collaborative interventional and observational studies that address the principal causes of perinatal mortality and morbidity. We have contributed significantly to that effort since 1992. The application describes past contributions and presents enhanced resources to meet the objectives of the Network. Specifically, we offer a strong and stable leadership and research staff in place since 1992; a larger and more diverse study population from 3 hospitals with a combined total of more than 14,000 annual births; a larger faculty & staff including 17 MFM clinicians, an MFM-geneticist, a perinatal epidemiologist, a research psychologist, 37 obstetrical sonographers, 8 research nurses; and a mature research infrastructure now enhanced by participation in OPQC - a statewide perinatal quality collaborative, the NICHD Nullipara Network, the North American Fetal Treatment Network, and OPRN - a regional perinatal research repository with an improved data system, all supported by a CTSA grant and located in an institution led by a Vice President of Health Sciences who is a MFM physician with Network experience. Our 2 satellite sites and their faculty have experience in clinical research, a long history of collaboration with OSUMC, and unique expertise in perinatal sonography. With support from the University, the College of Public Health, and the Ohio Department of Health, we are building a team of researchers in the medical center and main campus dedicated to unraveling the causes of racial and ethnic health disparities in pregnancy. Our relationship with Nationwide Children's Hospital in clinical care and research has never been stronger, and includes the perinatal research repository and targeted programs to reduce preterm birth. One such program described in our concept proposal is a RCT of interventions to prolong the inter-pregnancy interval as a method to reduce preterm birth. We look forward to continuing our tradition of service and innovation in the next cycle of the NICHD MFMU Network. PUBLIC HEALTH RELEVANCE : MFMU Network research is directed at pregnancy and perinatal disorders that have lifetime health consequences costing billions of dollars annually. Clinical investigations of the causes of perinatal and infant mortality and morbidity and their ultimate prevention require large numbers of study subjects that can only be recruited from multiple collaborating sites such as the one described in this application.